title: The Role of Chlorhexidine on Endotoxin Penetration to the Implant-Abutment Interface (IAI).
abstract: OBJECTIVE
  The aim of this study is to assess the risk of endotoxin penetration to the implant-abutment interface (IAI) of implants with Morse-taper connection and the effect of chlorhexidine in the prevention of such penetration.
  
  
  METHODS
  Thirty implants with Morse-taper connection were divided into three groups (n = 10/group) based on type of inoculation of the internal aspect of the implant. Implants in Group 1 were inoculated with 1 μl Escherichia coli for 24 hours; supernatant was removed and 0.5 μl of sterile saline was added. Implants in Group 2 were inoculated with 1 μl E. coli for 24 hours; supernatant was removed and 0.5 μl 0.2% chlorhexidine solution was added. Implants in Group 3 were inoculated with 0.5 μl of sterile saline and served as controls. Following inoculation procedures, implants were connected to standard abutments, immersed in sterile culture media, and loaded with 200,000 cycles of 160 N in a wear simulator. Samples were collected from the supernatant solution of each implant for endotoxin identification at the beginning of the loading cycle (T0) and following 9 hours (T9), 18 hours (T18), 27 hours (T27), 36 hours (T36), 45 hours (T45), and 54 hours (T54).
  
  
  RESULTS
  For Group 1 and Group 2, there were statistically significant differences between the endotoxin concentration at T0 and the endotoxin concentration at the subsequent sampling points (p < .05 Kruskal-Wallis with Bonferoni corrections for intragroup comparisons). There were no statistically significant differences between Group 1 and Group 2 at all sampling points.
  
  
  CONCLUSIONS
  This study indicates that bacterial endotoxin can penetrate the IAI of implants with Morse-taper connection, and 0.2% chlorhexidine solution had no significant effect on that penetration.
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
authors.forename: Theofilos
authors.initials: T
authors.lastname: Koutouzis
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
authors.forename: Hana
authors.initials: H
authors.lastname: Gadalla
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Kettler
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
authors.forename: Amelsaad
authors.initials: A
authors.lastname: Elbarasi
authors.affiliation: Department of Global Scientific Affairs-Clinical Research, DENTSPLY Implants Manufacturing GmbH, Mannheim, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Nonhoff
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D000044:Dental Abutments / Q000382:microbiology*; D015921:Dental Implants / Q000382:microbiology*; D003763:Dental Leakage / Q000382:microbiology* / Q000517:prevention & control*; D017267:Dental Prosthesis Design; D004731:Endotoxins; D004926:Escherichia coli; D008422:Materials Testing; D013499:Surface Properties
chemical_list: D000891:Anti-Infective Agents, Local; D015921:Dental Implants; D004731:Endotoxins; D002710:Chlorhexidine
keywords: chlorhexidine; dental implant; endotoxin; implant abutment; in vitro